From an older thread...
How "Powerful" or "Not Powerful" a hedge mage is, is specifically related to if they possess The Gift or not. Attempting to bring someone without the Gift into the Order is a sure way to crater someones reputation.
The Lineage of Pralix (HoH:S, p.126) is the most important entity in actually bringing a hedge mage into the Order. They are the specialist at it and recognized among the Order as such.
When a wizard seeks to join the Order of Hermes, he is usually directed towards a member of the Lineage of Pralix. Only those who possess The Gift are normally considered for membership. Those magi from other Houses who actively seek out hedge wizards (notably House Flambeau) are aware of the tradition, and recognize the service that they perform for the Order.